[Structural resistance of receptor organs of the vestibular apparatus to the factors of space flight].

Observations made in ground-based simulation studies and in real orbital flights on fish and amphibian larvae as well as on adult rats show that exposure to different space flight factors, particularly microgravity, for as long as 20 days produces no pathological changes in the structural organization of vestibular receptors. However the possibility of functional or adaptive rearrangements in maculae and crystae as well as in the otolith organ cannot be excluded. It appears that bony fish (Teleostei) are most suitable for the study of adaptive changes in the otolith apparatus. When examining ultrastructural changes in maculae and crystae, it is important to take into consideration spatial and structural nonhomogeneity of the receptor epithelium of vestibular organs.